// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef DRACO_POINT_CLOUD_POINT_CLOUD_BUILDER_H_
#define DRACO_POINT_CLOUD_POINT_CLOUD_BUILDER_H_

#include "draco/point_cloud/point_cloud.h"

namespace draco {

// A helper class for constructing PointCloud instances from other data sources.
// Usage:
//   PointCloudBuilder builder;
//   // Initialize the builder for a given number of points (required).
//   builder.Start(num_points);
//   // Specify desired attributes.
//   int pos_att_id =
//       builder.AddAttribute(GeometryAttribute::POSITION, 3, DT_FLOAT32);
//   // Add attribute values.
//   for (PointIndex i(0); i < num_points; ++i) {
//     builder.SetAttributeValueForPoint(pos_att_id, i, input_pos[i.value()]);
//   }
//   // Get the final PointCloud.
//   constexpr bool deduplicate_points = false;
//   std::unique_ptr<PointCloud> pc = builder.Finalize(deduplicate_points);

class PointCloudBuilder {
  public:
    PointCloudBuilder();

    // Starts collecting point cloud data.
    // The behavior of other functions is undefined before this method is called.
    void Start(PointIndex::ValueType num_points);

    int AddAttribute(GeometryAttribute::Type attribute_type,
                     int8_t num_components, DataType data_type);

    // Sets attribute value for a specific point.
    // |attribute_value| must contain data in the format specified by the
    // AddAttribute method.
    void SetAttributeValueForPoint(int att_id, PointIndex point_index,
                                   const void *attribute_value);

    // Sets attribute values for all points. All the values must be stored in the
    // input |attribute_values| buffer. |stride| can be used to define the byte
    // offset between two consecutive attribute values. If |stride| is set to 0,
    // the stride is automatically computed based on the format of the given
    // attribute.
    void SetAttributeValuesForAllPoints(int att_id, const void *attribute_values,
                                        int stride);

    // Finalizes the PointCloud or returns nullptr on error.
    // If |deduplicate_points| is set to true, the following happens:
    //   1. Attribute values with duplicate entries are deduplicated.
    //   2. Point ids that are mapped to the same attribute values are
    //      deduplicated.
    // Therefore, if |deduplicate_points| is true the final PointCloud can have
    // a different number of point from the value specified in the Start method.
    // Once this function is called, the builder becomes invalid and cannot be
    // used until the method Start() is called again.
    std::unique_ptr<PointCloud> Finalize(bool deduplicate_points);

  private:
    std::unique_ptr<PointCloud> point_cloud_;
};

}  // namespace draco

#endif  // DRACO_POINT_CLOUD_POINT_CLOUD_BUILDER_H_
